Conventionally, a position detector apparatus may be used to detect a rotation angle of a throttle valve of an electric-control throttle apparatus, a rotation angle of an accelerator pedal in an accelerator pedal module, or a stroke amount of a clutch actuator.
For example, a patent document 1 (i.e., Japanese Patent No. 4367473) discloses an electric-control throttle apparatus, which uses a position detector apparatus for detecting a rotation angle of a throttle valve. The position detector apparatus has dual Hall ICs that function together as a detector element for detecting a magnetic field of a magnet that is disposed on an end of a rotation shaft of a throttle valve. The position detector apparatus used in such an electric-control throttle apparatus is a resin-molded product, which molds the wiring extending from the two detector elements and a terminal connected thereto together with the respective detector elements as a pre-assembly part or a first pre-assembly module. Such a position detector apparatus is resin-molded together with a soldered terminal that is soldered to the above-described terminal to be installed in a housing cover of the electric-control throttle apparatus.
The position detector apparatus to be used in various products as described above may be installed in a single detector product or may be installed in a dual detector product.
Therefore, by preparing the position detector apparatus as a single detector first pre-assembly module that resin-molds only one detector element, such a single detector first pre-assembly module may be used in both of the single detector product and the dual detector product. In such a case, the position detector apparatus is preferably made as a resin-molded product in which the detector element, the wiring, and the terminal are resin-molded together, to improve the rigidity of the molded product.
However, when one detector element is resin-molded together with the wiring and the terminal, a dynamic pressure of the melted resin that is injected into the mold during injection molding may be applied to the detector element, which may result in a dislocation of the detector element in the mold during the injection molding and cause a faulty pre-assembly module that has the detector element dislocated in a resin part of the module.
Further, the patent document 1 discloses an electric-control throttle apparatus, which uses a position detector apparatus for detecting a magnetic field of a magnet that is disposed on an end of a rotation shaft of a throttle valve, for detecting a rotation angle of such throttle valve.
The position detector apparatus is a resin molded product, which molds a Hall IC and a terminal soldered onto a lead frame of the Hall IC, to form a first pre-assembly module. Such a position detector apparatus is further molded from resin to make a secondary pre-assembly module, i.e., a one-body combination of (i) the first pre-assembly module and (ii) a housing cover of the electric-control throttle apparatus.
Generally, in the position detector apparatus, a very thin resin wall is molded around the Hall IC to form the first pre-assembly module. In such manner, the position accuracy of the Hall IC against the outer wall of the first pre-assembly module is guaranteed.
However, when the first pre-assembly module is molded by injection molding, the position of the Hall IC may be dislocated from an intended position in an inside of a metal mold, and such a dislocation of the Hall IC may lead to an exposure of a portion of the Hall IC beyond the resin wall of the first pre-assembly module, due to a contact or a closeness of the dislocated Hall IC to an inner wall of the metal mold. In a worst case scenario, water or a liquid intruding into an inside of the first pre-assembly module from a Hall IC exposure part may corrode the lead frame and/or the terminal of the Hall IC and may deteriorate the position detection accuracy of the position detector apparatus.